Guest Stars Jeff Bennett voices Choose Goose Hynden Walch voices Princess Bubblegum Steve Little voices Peppermint Butler Tom Kenny voices Berdzerd Anthony Stewart Head voices Con Wizard Bill Hader voices Bufo Toks Olagundoye voices Dr. Caledonius Bex Taylor-Klaus voices Blaine Maurice LaMarche voices Skull Maurice LaMarche voices Wizard Cop #1 Edi Patterson voices Cat Student Edi Patterson voices Momdebra Dana Snyder voices Life Giving Magus Dana Snyder voices Potable Wizard Duncan Trussell voices Ron James Julia Butters voices Larry Steve Little voices Abracadaniel Patti Harrison voices Weapon Head Sheng Wang voices Dimension Wizard Chloe Coleman voices Cadebra SungWon Cho voices Brain Wizard SungWon Cho voices Wizard Cop #2 John Omohundro voices Spader Cole Sanchez voices Little Dude Co Starring John DiMaggio voices Additional Voices Tom Kenny voices Additional Voices Jeremy Shada voices Additional Voices Pendleton Ward voices Additional Voices Niki Hyun Yang voices Additional Voices Cole Sanchez voices Additional Voices Jeff Bennett voices Additional Voices Bex Taylor-Klaus voices Additional Voices Julia Butters voices Additional Voices SungWon Cho voices Additional Voices